Threaded or Press Fit?
 

I searched for a thread and couldn't find one - I apologize if this has been beaten to death.

My simple question is, are pressed fit bottom brackets inferior to threaded? Would the members of this forum base a purchase decision (all things being somewhat equal) on what type of bottom bracket a bike has?

If I had the choice between two bikes that were identical in all ways but the bottom bracket, I'd take threaded every time.

You're just trying to start a fight, aren't you?

On the off chance that this isn't a troll job, I'll say that BB type is a factor, but it's pretty low on the priority list and that none of the common BBs are non-starters for me. Others will certainly disagree.

Not a troll and not trying to start anything. I have been looking at several bikes - Tarmac (I currently ride a Roubaix), Addict RC, etc. - and some have threaded while others have pressed fit. There are several videos and articles on the internet, but I am looking for opinions from this group.

I'll fully admit that I have not owned a press-fit BB bike, and that my current attitude towards them is misinformed, that all it takes is proper setup and press-fit is fine, blah blah blah. But no, I wouldn't buy a bike with press-fit bearings. With no personal experience with them, all I have to go by is the horror stories I've seen online about them. They abound.

To my ears, arguments like "press-fit are actually awesome, it's just that manufacturers don't keep tolerances tight enough to work well with them blah blah blah" sound exactly like "communism is actually pretty awesome, it's just that the Soviet Union and China did communism wrong blah blah blah."

I have noticed that more manufacturers are heading towards threaded ( especially on mid range bikes) my wife just picked up a Roubaix (105 equipped, I forget the level, but mid for sure), and it was spec'ed with a BSA BB. Pinarello has never wavered from Italian threaded BBs, and I think most will agree that they are top notch. rumors are that Trek is heading toward the T47 threaded standard. etc. seems like threaded might weigh more, but I for one like having that little bit of metal in the BB area, since it takes all the force I have to give (as lowly as that might be!).

1) you're not going to find consensus. 2) the problem with your "all other things ~equal" scenario is that all other things are never equal, so you have to decide how to weight the factors. You. Not others - you. For me, BB type is probably less important than the colorway. For others, BB type is a deal-breaker.

:fight:

Threaded BBs are pretty much idiot proof. They are reliable, easy to remove and install and relatively cheap. I have bikes with English threaded, Italian threaded, BB 30 and BB 86. All work well. However, I prefer threaded for the reasons previously mentioned.

There are so many types of press fit designs, that you should look at the specific type in question. Do a search for Hambini. He has videos where he describes what he feels to be the shortcomings of some designs. I know the BB86 is considered to be OK. There also some pricey bottom brackets that screw together, but fit into a press fit frame. I've got two bikes with BB86 that are working OK. I use Campy drive trains, so all that presses into the frame are aluminum cups, that match the bearing that Campy presses onto the spindles.

Threaded BBs still use a pressfit interface between the bearing and the BB unit. Pressfit bottom brackets attempt to eliminate redundancy (mainly to reduce costs and weight).

The big issue here is that it’s relatively easy to make a precise aluminum or plastic BB unit to press bearings into. It’s NOT easy to make a precise carbon shell. You should avoid systems that press bearings directly into the carbon frame for this reason.

You’ll see many systems that have a plastic BB unit that the bearing presses into:

https://cimg5.ibsrv.net/gimg/bikefor...836cbab7b.jpeg
That plastic exists to deform to the imperfect carbon BB shell in the frame. It’s also a sacrificial layer to keep your hard steel bearings from wallowing out your BB shell.

Threaded BBs are easier to service for the home mechanic and provide a floor in terms of tolerances and fit. You know that the bearing will not be crushed by an undersized shell or move around (creak) due to an oversized shell. However, the door remains wide open for misalignment unless the manufacturer chooses to use a one-piece shell.

If I cared a lot about performance, I’d get a wide pressfit frame (like BB386EVO or BB86) with a one piece alloy bottom bracket like Hambini or BBinfinite. A thread together BB like wheels mfg would also work really well and be just as easy to service as a threaded BB. I would not use a cheap plastic BB that is designed to deform.

If I cared about serviceability or wanted some reassurance about quality, I would go with threaded. Just understand that a threaded BB will not inherently be perfect.

My impression is most pressfit problems can be solved with the right aftermarket solution, e.g., a one-piece or screw-together shell, that fixes the bad alignment. Not true?

I have only experience with my Cervelo C3's BB30 for press-fit, but I'd take that over any of my old threaded BBs any time. The difference in rigidity is quite obvious. Either I'll invest in tools for it when the time comes to service it, or I'll have a local shop do it. (Frankly I have no idea what's needed, if anything at all.)

The easiest fix is to take it the store you bought it from and have them fix it under warranty. This may require swapping out the frame, but they can do that easily enough; it's just 2-3 hours' work for someone who builds them up for a living.

Most, but not all. BB90, in particular, has few options because it's pressed directly in to the frame and made with the smaller 24mm spindles in mind, so those two limiting factors back you in to a bit of a corner. There may be some thread-together aftermarket solutions, but the bearings would probably have to be a bit undersized to accommodate the dimensions.

All that said, I have a Trek with BB90, it's been fine, I have confidence in their lifetime warranty (for the original buyer) and it wouldn't keep me from buying something like a Madone, if I were in the market.

I had a Trek that creaked like an old staircase. I Had a BB Infinite bottom bracket installed. Now it spins smoothly with no noise.

I've had several BB30 (8), PF86 (4) and regular threaded BBs (7) frames. They all have strengths and weaknesses, but if installed properly, they are all fine. I honestly would not base my frame purchase on the BB - except to avoid Trek BB90.

Yes, threaded are a bit more idiot proof, but that doesn't mean someone hasn't cross threaded theirs by getting the cups backward.

Also, I'm a big fan of Wheels Mfg. BBs. They work well and hold up.

I am a bike mechanic although I don't work as such in a retail shop. I do my own work and will work on others bikes at times if they ask me. I would not have a press fit BB if I could get a threaded. Press fits can work but they normally require more work and have more trouble. The threaded is not broke and it changed just because it was easier to do a frame for press fit than threaded. All my bikes of the past 10 years I never once had an issue with the BB. That is probably 50000 miles and they work fine. I am partial to shimano because I believe they have the best front crank performance over the rest. I admit that I don't know Campy but Camp is great stuff I just don't want to buy more tools.

I have road Treks BB90 and they don't seem any stiffer or better than threaded, although they are nice bikes. I hope specialized will return to thread because they I could at least look at one of their bikes. These days though I find Ti to be the best and they are usually thread BB.

I wouldn't care too much. I'm buying the bike I want for other reasons and the bb type is not going to be the deal breaker. Sure, some have horror stories, and that should be taken into account. But an overriding number are likely having few if any issues.

Besides, won't you need an excuse to get another bike in a few years?

Threaded.

Anything but BB90...

Ahem, excuse me, I am THE better idiot. :lol:

But yeah, I prefer threaded BBs. One of my deRosa has PF30 BB. I used a BBinfinite (threads unto itself) to avoid any potential creaks

I have had both and properly installed, PF BBs are fine. My first time with one of these wasn't as good but all it took was using he correct loctite and primer. My Look 675 had BB85, my current Cervelo S5 has BBRight and I made sure to buy the Loctite and primer myself and let the mechanic know to use them (at this point I won't assume that any mechanic knows wth they're doing due to some bad experiences) and it's rock solid. YMMV.

I have two De Rosa Protos. A 2016(made in Italy) and a 2020 (made in “elsewhere”—quote from De Rosa guy).

The later has a threaded. I wonder why they changed. The press never did give me any issues.

even Trek is admitting defeat
 

and did away with PF in favor of trying T47 threaded. yea!